β-Adrenergic Antagonists

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General Principles

Definition

Of all of the agents available, propranolol tends to exhibit the most toxicity because it is lipophilic, is widely distributed throughout the body, and possesses significant membrane-stabilizing activity. Sotalol, which is classically thought of as a class III antiarrhythmic, also has some β-adrenergic antagonist activity and, in toxic doses, can result in a prolonged QTc and TdP.

Classification

Cardiovascular agents are a frequent cause of serious poisonings and, according to the 2017 annual report of the National Poison Data System, were the eighth leading cause of fatal drug exposures.1 Patients with these overdoses require aggressive intervention and close monitoring.

Pathophysiology

The toxicity associated with an overdose of β-blockers is largely due to the effects of antagonism at catecholamine receptors. In general, selectivity is lost in overdose, so bronchospasm may occur in the setting of β1-selective antagonists.

General Principles

Definition

Of all of the agents available, propranolol tends to exhibit the most toxicity because it is lipophilic, is widely distributed throughout the body, and possesses significant membrane-stabilizing activity. Sotalol, which is classically thought of as a class III antiarrhythmic, also has some β-adrenergic antagonist activity and, in toxic doses, can result in a prolonged QTc and TdP.

Classification

Cardiovascular agents are a frequent cause of serious poisonings and, according to the 2017 annual report of the National Poison Data System, were the eighth leading cause of fatal drug exposures.1 Patients with these overdoses require aggressive intervention and close monitoring.

Pathophysiology

The toxicity associated with an overdose of β-blockers is largely due to the effects of antagonism at catecholamine receptors. In general, selectivity is lost in overdose, so bronchospasm may occur in the setting of β1-selective antagonists.

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